No problem, i will considere your suggestion if i implement multi 2FA systems in one plugin. On first hand, i will release only a Google Authenticator plugin, after why not create a centralized plugin with all 2FA systems and release each systems seperatly if someone one just want one implementation. I will think about that. Okay for the U2F USB keys, i don't know how the system work at the moment, i'm waiting my key to be delivered to start working on it !
The "problem" is if i make sub-ui for 2FA, other developers needs to implement their methods in, and you need to install my plugin. It's a bit complicated. But i will test in the future how i can do it better. Multiple keys for 2FA? Hum, it's a security breach to allow this in my mind, with the QR-Code you can add the system to many devices you want. If you have lost your device for exemple, it think to implement email recovery to disable the system or show a "unique" recovery key. (In last, the user can contact board administrator)
I'm just working on an IPS 4 Plugin to support 2-FA Authentication with Google (Board and ACP). And i've already heard of FIDO U2F technology, and you convinced me, i've just bought an Yubico U2F key to make test and why not a plugin
Just to answer to Cabola's question. But for me, local upgrade to IPS 4 from 3.4.7 under localhost or localhost/myforum or 127.0.0.1 or 127.0.0.1/myforum don't work. Already explained to support. Upgrade checker want a valid license to continue to the next step.... The solution is to replace the controller which is called by the script itslef in the URL to bypass licensing step. (license to applications) So, upgrade / install will continue with no license. And Dashboard will inform you that you don't have license. Welcome in DRM century...
Most of the time, they don't have Client account. They have an unlicensed software and didn't know that they need a verified account to download files from IPS.
it is part of the profits to own a legal license.